Apparatus for drying webs by radi



Sept. 23, 1947.. F. w. ADAMS 2,427,892

APPARATUS FOR DRYING WEBS BY RADIANT AND CONVECTIPN HEATING Filed Oct. 16, 1944 JNVENTOR. EWADAMS BY @Mw 55mm A TTOBNE'V Patented Sept. 23, 1947 APPARATUS FOR DRYING WEBS BY RADI- ANT AN'D CONVECTION HEATING Floyd W. Adams, Los Angeles, Calif., assignor to Los Angeles Paper Box Factory, Los=Angeles, Calif., a corporation of California Application October 16, 1944, Serial No. 558,869

3 Claims.

My invention relates to a process and apparatus for drying moisture-carrying paper or cloth, drying printing ink on paper or cloth, etc., and an important object of the invention is to provide an apparatus and process for drying or evaporating moisture or other evaporable substance from a continuous web of material without the web contactin heated, metal surfaces.

Another object of the invention is to provide mechanism for drying the material by exposing same to drying means on one side only, at a time, while withdrawingmoist air from the opposite side of the web from the drying means.

Still another object is to provide means for using radiant energy in such an apparatus and process as distinguished from heat by convection currents.

A further object is to provide in such a drying or evaporating process, an arrangement whereby the web first has a very easy flight, at a time when the web carries the most moisture, and, if paper, is quite weak.

My invention also has for its object to provide such apparatus that is positive in operation, convenient, simple and economical to use, easily and economically erected, both as to cost of equipment and saving in building costs, and of general superiority and serviceability.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description. However, the drawings merely show and the following description merely describes one embodiment of the present invention, which is given by way of illustration or example only.

In the drawings, like reference characters designate similar parts in the several views.

Fig. 1 is a diagrammatic vertical section through apparatus embodying the foregoing characteristics and adapted to carry out the foregoing process.

Fig. 2 is a section along the line 2-2 of Fig. 1.

Fig. 3 is an enlarged transverse section through a burner element comprised in the invention.

Fig. 4 is an enlarged section taken on the line 4--4 of Fig. 2.

Fig. 5 is a broken side elevation looking in the direction of arrow 5 of Fig. 4.

Referring more in detail to thevdrawings, the reference number I generally indicates a housing for my present apparatus provided with a stack 8 having therein a fan 6 adapted to draw air from within the housing I and blow it out through the 'drive the fan. A spider I2 supports the motor within the stack.

A plurality of hot air ducts 43 to 48 have laterally facing louvres 49 for supplying hot air into the housing 1 at different elevated points and in- 7 side and outside of the loops of a web [5 of moisture-carrying paper or cloth, or a web of material carrying freshly imprinted printing ink. The ducts may have louvres facing in other directions too if desired, e. g., duct 48 has the laterally facing louvres 50 and also a downward facing louvre 5|. Conduits l8 connect the ducts 43 to 48 with a suitable source of hot, comparatively dry air (not shown). The ducts 43 to 48 are arranged either inside or outside the loops, or both.

Likewise disposed at dispersed points along the path of the web l5 are ribbon gas burners adapted to generate radiant energy.

I find that this type of drying means i more economical in the long run than devices producing mere convection currents such as a steam radiator or other convection heater. By my present means greater speed and greater economy are efiected in the end.

I apply the heat by radiation in such manner that the greater portion of the energy radiated from the burners is converted int heat substantially only when the web I5 is impinged by the radiant rays.

My present apparatus is more economical of the heat energy than when steam is used, since a steam requires multiple transfers of heat, to wit, from a burner to a boiler, from the metal of the boiler to the water in the boiler, and from the steam to heating drums for the web I5. I transfer the heat from the present ribbon burners directly to the web.

I stagger the arrangement of the ribbon burners so that nothing will prevent the escape of steam from the web on the side opposite each ribbon burner. I face one side of the web l5 to the radiant energy, then the other side. In the early stage, if the web is water-saturated paper, it is a major portion water and is very weak. A relatively large roller l6 on a shaft ll connected to be driven by a pulley I4, directs this weak web downwardly in an easy flight to a roller 19 and the web travels partially therearound and down to a still lower roller 20. A ribbon burner 2| is arranged between the rollers l9 and 20. The web then has strength enough to travel upwardly 3 slightly to a roller-22 and therefrom to roller 23 thereabove.

Ribbon burners Z4 and 25 are respectively disposed between the rollers 20 and 22 and the rollers 22 and 23. The rollers I9, 20, 22 and 23 define a loop around which the web travels.

One of the hot air ducts, to wit, 43 is arranged outside said loop, on the opposite side of the web from the ribbon burners 20, 24 and 25, to aid in absorbing moisture driven from the web l5. From the roller 23 the web is looped in the opposite direction from the first mentioned loop, so that the opposite side of the web is on the inside of the second loop. The second loop is defined by the rollers 26 to 30, inclusive. Ribbon burners 3! to 34, inclusive, are arranged inside the loop between adjacent pairs of the rollers 26 to 30.-:-Also arranged inside the loop are hot air-ducts 44 and 45, one above the other.

,From the roller 30 the web travels down around the rollers 35, 36 and 31. Radiant energy burners 38 and 39 are arranged between adjacent pairs of the rollers 35 and 36 and 36 and 31.

It is to be understood that the rollers I9, 20, 22, 23, 26 to 30, and 35 to 31 are driven rollers, driven at the same peripheral speed as the initial feed roller 16. Pulleys 53 are arranged at opposite ends of said small rollers which are supported at their outer ends in one wall of the housing 1, while the inner ends thereof are free of the other wall, providing thereby a space for the ready, lateral escape of the moisture-laden air. Suitable driving belt means 54 and 55 at opposite ends of the rollers may be driven by motor means (not shown) of conventional form.

The radiant burners are fed by a conduit system 58 that connects with a T-head 51. Pipes B and 59 fed by pumps 60 and BI respectively supply gas (such as ordinary illuminating gas) and air to the system 56 in measured quantities through the T-head. A motor 62 drives the pumps through the intermediary of the shaft 63. Pipes 64 and 65 respectively feed gas and air to the pumps 60 and 6|. The source of the gas is not shown.

The radiant ribbon burners comprise elongated pipe members 66 that are largely curved in cross section, as shown in Fig. 3. Flanges B1 fan out at opposite sides of spaced ceramic plates 68. A central plate 69, in the space between the more extended plates 68, has a plurality of long, smalldiameter holes therethrough. This arrangement has been found to produce maximum, uniform combustion. These ribbon burners provide radiant energy that effectively drives moisture from the web l5 or dries printing ink, if any, thereon, when the rays from the burner strike the web.

The operation is believed clear to those skilled in the art. Briefly, it includes running a, freshly formed water-saturated web of paper or cloth, or a freshly printed web of material over an initial feed roller I6 and downward in an easy flight. From there the web passes around rollers to form a loop. Inside the loop, radiant energy burners drive the moisture from the web or dries printing ink thereon, and hot air duct means on the opposite side mixes the vapor-carrying air with hot, dry air and the fan means 6 withdraws the mixture from the housing through the stack 8.

The next loop reverses the web so that the opposite side is on the inside of the loop. Hot air ducts are both inside and outside of the ,second loop. The hot air again takes up moisture or vapor in the air and the mixture is drawn out through the stack 8. The radiant energy burners are on the inside of the second loop, the same as the first.

It is believed clear without further illustration that the loops may be multiplied as many times as required to completely dry the paperor cloth or dry printing ink thereon, by the time the web is discharged from the drying housing 1.

While I have illustrated and described what I now regard as the preferred embodiment of my invention, the construction of the apparatus and the steps and the sequence of steps of the process are of course subject to modification without departing from the spirit and scope of my invention. I, therefore, do not wish to'irestrict myself to the particular form of construction illustrated and described, nor to the steps or sequences of steps of the process described hereinbefore, but desire to avail myself of all modifications that may-fall within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. An apparatus for drying a continuous web of material containing evaporable constituents, comprising a chamber, a series of upper and lower driven rollers supported in one wall of said chamber and free of the other wall for forming the web into a continuous series of upper and lower loops and for continuously conveying the web thereover, radiant energy producing means within the upper and lower loops, said means being disposed at points spaced about the arcs of and in proximity to said loops, said loops having free communication with said chamber at one side to permit escape of vaporized material to the chamber, ducts transversely disposed within said 10 'ps and provided with laterally facing louvres. means for supplying hot, substantially dry air to said ducts for direction against said loops at points between said spaced means to aid in removing vaporized material from the inside of said loops, transversely disposed hot air ducts for supplying hot air currents to the outside of said loops at points between said means, and means for withdrawing the vapor-laden air from said chamber.

2. An apparatus for drying a continuous web of material containing evaporable constituents. comprising a chamber, a, series of upper and lower driven rollers supported at one end in one wall of said chamber and at the other end free of the other wall of the chamber to provide a sparse, said rollers being adapted to form the web intd a continuous series of upper and lower loops and to convey the web continuously thereover, the web presenting outside and inside surfaces in its travel over said rollers, radiant energy producing means disposed at spaced points about the arcs of and in proximity to the outside surface of said lower loop and about the arc of and in proximity to the inside surface of said upper loop, said loops having free communication with the space between the ends of said rollers and the wall of said chamber to permit the lateral escape of vaporized material to the chamber, ducts within the upper loop and provided with lateral, oppositely disposed louvers, means for supplying hot air to said ducts for direction against the inside of said upper loop at points staggered with respect to said energy producing means to disperse vaporized material therefrom, transversely disposed hot air ducts for directing hot air currents to the outside of said loops, and means for- 7 5 withdrawing the vapor-laden air from said chamber.

3. An apparatus for drying a continuous web of material containing evaporable constituents, comprising a chamber, a series of arouately arranged spaced lower and upper rollers supported in said chamber and free of at least one wall of said chamber to provide a. space in open communication with the chamber, said rollers being adapted to form the web into a continuous series of lower and upper loops and to convey the web continuously thereover, radiant energy means disposed at spaced points about the arcs of and in proximity to the surfaces of said loops, said loops having free lateral communication with the space between said rollers and the wall of said chamber to permit the lateral escape of vaporized material to the chamber, a plurality of oppositely disposed nozzles within the upper loop, staggered with respect to said radiant energy means, means to supply heated air to said nozzles for direction against the inside of said upper loop to disperse vaporized material laterally therefrom, nozzles disposed on the outside of said upper loop, and means for exhausting the vapor-laden air from said chamber.

FLOYD W. ADAMS.

REFERENCES CITED The following references are of record in the file of this patent:

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